Intra-abdominal meconium calcifications in the fetus can be detected with sonography.t-3 Fetal peritoneal calcifications are usually related to meconium peritonitis secondary to bowel perforation; intraluminal calcifications (enterolithiasis) are relatively rare but are often associated with bowel obstruction. 2.3 Sonographic characteristics clearly reveal the presence of calcified meconium and may distinguish intraluminal from peritoneal foci. The following is a report of two cases of prenatal detection of calcified intraluminal meconium associated with anorectal atresia. Sonographic signs useful in the antenatal diagnosis of enterolithiasis are described. To our knowledge, these have not been previously reported.
CASE REPORTSCase 1 A multiparous 37-year-old woman without significant medical history presented to the obstetrics service with a 2-day history of dysuria and lower abdominal cramping. Sonography demonstrated a 30-week gestation and oligohydramnios. Fetal survey revealed a small thorax, right hydrone- phrosis, nonvisualization of the left kidney, and a dilated loop of bowel in the midabdomen. The bowel loop "mass" contained multiple coarse, highly reflective foci, 4-to 6-mm in diameter, compatible with calcifications (Fig. 1). Peristalsis in this segment was present. Four days later the patient delivered a 1,575-g girl with Apgar scores of 4 and 6. Delivery was com• plicated by breech presentation and amnionitis. The baby was noted to have multiple congenital anomalies and expired 5 hours postpartum. Postmortem examination demonstrated imperforate anus, bilateral renal hypoplasia with right uretero~ pelvic junction obstruction, Potter's facies, choledochal cyst, imperforate vagina, urachal cyst, and a colon that ended blindly against the dorsal aspect of the latter. Several mesenteric bands surrounded a distal loop of dilated sigmoid colon. Specimen radiographs of the meconium within the loop demonstrated scattered calcifications. No connection between the urachal sac and colon was identified. The infant's karyotype was 46,XX. An abdominal radiograph performed after expiration identified scattered left hemiabdominal calcifications confined to a focally dilated loop of colon (Fig. 2).Case 2 A 33~year-old gravida 1, para 0 woman with no significant medical history was suspected of carrying a growthretarded fetus. Sonography demonstrated a 32-week gestation. The fetal abdomen contained multiple coarse hyperechoic foci within dilated loops of bowel (Fig. 3). Active peristalsis of these loops was observed. A fetal sonogram 3 weeks later demonstrated normal interval growth and multiple coarse intra-abdominal calcifications confined to the dilated bowel that measured 4.5 em in diameter in the periphery of the fetal abdomen. A 2,296-g boy was delivered by cesarean section following a nonreactive stress test. Apgar scores were 9 and 9. Neonatal evaluation demonstrated imperforate anus, hypospadias, rectovesical fistula, malpositioned thumbs, and mul-